KeepIf Command
From GeoGebra Manual
- KeepIf( <Condition>, <List> )
- Creates a new list that only contains those elements of the initial list that fulfil the condition.
- Example:
KeepIf(x<3, {1, 2, 3, 4, 1, 5, 6})
returns the new list {1, 2, 1}.
- Note: For list of numbers arbitrary condition may be used. For list of other objects one can use only conditions of the form
x==constant
orx!=constant
.
- KeepIf( <Condition>, <Variable>, <List> )
- This syntax allows a more flexible condition.
- Example: For Points P, Q, R
KeepIf(x(A) < 3, A, {P, Q, R})
will filter the points whose x-coordinate is less than 3 out of the list. The variable A is replaced in turn with P then Q then R for the check.